Heretofore, it has been known to provide coupler carrier wear plates of hardened steel welded to long-shank couplers. These wear plates were frequently lost due to poor welding techniques or for other various reasons, thereby allowing the bare shanks to contact the high-carbon coupler carriers that in turn suffered heavy wear on the cast steel coupler shanks. These long-shank couplers are found on extra long railroad cars and require a bellmouth of a width more than twice the standard bellmouth in order to permit negotiation of standard and non-standard curves. It is these coupler arrangements where wear plates have not been used successfully. Manganese carriers and other non-metallic carriers have been provided for wide bellmouth applications. Manganese carriers are not weldable to the coupler carrier because welding of manganese to cast iron is extremely difficult.
Secondly, flatness requirements of such a wear plate are needed for longevity and such requirements exceed the manufacturing tolerances for manganese.
Non-metallic wear plates usually cannot withstand the extremely heavy loading pressures demanded by long-shank couplers, thereby resulting in early failure. Recently, the requirement for equipping long shanks of couplers with shank wear plates has been discontinued. Accordingly, the problem of wear experienced with the coupler shank and the carrier tends to reduce the effective lifetime of the shank and/or carrier, thereby requiring early maintenance.